Cementitious dumbbell



Dec. 9, 1969 A JR 3,482,834

CEMEN'IITIOUS DUMBBELL Filed Aug. 31, 1967 3 Sheets-Sheet 1 INVENTOR. FORREST H. JAMES JR ATTORNEYS Dec- 9, F H JAMES R CEMENTITIOUS DUMBBELL 3 Sheets-Sheet 2 Filed Aug. 31, 1967 INVENTOR. FORREST H. JAMES JR am AT TORN EY S Dec. 9, 1969 F. H. JAMES, JR 3,482,834

CEMENTITIOUS DUMBBELL Filed Aug. 31, 1967 s Sheets-Sheet 5 INVENTOR. FORR EST H. JAMES JR.

ATTORNEYS United States Patent 3,482,834 CEMENTITIOUS DUMBBELL Forrest H. James, Jr., Opelika, Ala., assignor to Diversified Products Corporation, Opelika, Ala., a corporation of Alabama Continuation-impart of application Ser. No. 395,693, Sept. 11, 1964. This application Aug. 31, 1967, Ser. No. 673,241

Int. Cl. A63b 11/00 US. Cl. 272-84 Claims ABSTRACT OF THE DISCLOSURE A dumbbell having a monolithic core formed of a solidified cementitious material within a hollow plastic shell. The opposed heads of the dumbbell, which are spaced apart by the central handle, have inner faces which taper inwardly in frusto-conical fashion toward the ends of the handle and merge therewith along annular arcuate portions. The shell is filled through a filling opening with cementitious material from one end, as vibration is applied to the shell and the cementitious material, and a plug, submerged in the cementitious material, closes the filling opening. When solidified, the cementitious material shrinks to tighten the core in the shell and the plug in place.

This is a continuation-in-part of my copending application Ser. No. 395,693, filed Sept. 11, 1964 for Dumbbell and Means for Filling the Same and my copending application Ser. No. 507,886, filed Nov. 15, 1965 for Dumbbell, now abandoned.

This invention relates to exercising devices and is more particularly concerned with a dumbbell having a plastic shell and cementitious material therein.

Lightweight dumbbells are customarily turned from a single piece of wood while heavier dumbbells are commonly cast from a heavy metal, such as iron. In either case, the cost of manufacturing is considerable. The lightweight wooden dumbbells, while appropriate for esthetic types of exercises, are not appropriate for muscle building exercises, which are dependent upon the force required for manipulation, to be effective. The cast iron dumbbells, on the other hand, while adequate in weight, have disadvantageous features in that their surfaces are frequently rough and uncomfortable to grip, and cause damage to floors or other objects with which they may come in contact and are noisy, particularly when clashed to gether.

Briefly described, the barbell of the present invention is formed of a thin walled, unitary plastic resilient hollow shell having a solidified cementitious core within the hollow portion. The shell defines the shape of the dumbbell and includes a hollow central handle portion joining a pair of opposed communicating complementary head portions. The head portions are larger than the handle portion. Each head portion has a frusto-conical inner face wall and a frusto-conical outer face twall tapering in opposite directions from adjacent bases, the bases of the walls of each head being joined by a peripheral rim, arcuate in cross-section. The inner end of each inner face merges along an arcuate concaved junction portion with its associated end portion of the handle. One end of one of the heads is provided with a filling opening and the other end of the other head with a flat base plate.

The cementitious material is poured into the interior of the shell through the filling opening and passes downwardly through the hollow handle so as progressively to fill the lower head and then the handle and finally the upper head. A plug, inserted into the soft cementitious material through the filling opening closes the opening and is retained in place by solidification of the cementitious material.

Accordingly, it is an object of the present invention to provide a dumbbell which is inexpensive to manufacture and durable in structure.

Another object of the present invention is to provide a dumbbell formed of a plastic shell and cementitious material core in which the cementitious material is tightened in its position with respect to the shell when the cementitious material solidifies.

A further object of the invention is to provide a dumbbell of compound construction having an external surface of a relatively yieldable, but wear resistant material, and an interior of dense, hard and weighty material.

Another object of the invention is to provide a dumbbell of cast cementitious material such as concrete, either alone or with such weighting material as iron scale or the like.

Numerous other objects, features and advantages of the present invention will be apparent upon consideration of the following specification when taken in conjunction with the accompaying drawings, in which:

FIG. 1 is a longitudinal sectional view of the dumbbell of the present invention manufactured in accordance with the present method;

FIG. 2 is an end elevation of the dumbbell illustrated in FIG. 1;

FIG. 3 is a side elevation, partly in section, illustrating a method of and apparatus for manufacturing the dumbbell of FIGS. 1 and 2;

FIG. 4 is a sectional view of a fixture used in holding the dumbbell casing during filling with a fragmentary showing of the dumbbell casing seated therein:

FIG. 5 is a perspective view of the fixture shown in section in FIG. 4.

Referring to FIGS. 1 and 2 of the drawings, it will be seen that the dumbbell of the present invention, includes a hollow, unitary, thin walled, shell S formed of plastic, such as polypropylene or the like. The tubular shell S is symmetrical about its longitudinal axis and includes a pair of spaced opposed enlarged complementary hollow head portions 10 and 11 connected together solely by the hollow cylindrical handle portion 14. The interior of the shell S is hollow throughout so that there is communication along the axis of the dumbbell between head portion 10, handle portion 14, and head portion 11 for receiving, in a fluid condition, the cementitious material, which when solidified, forms the monolithic core C.

Each of the heads or head portions 10 or 11 is angular in cross-section with the inner and outer face walls 12 and 13, respectively, in the form of truncated cones joined at their bases by annular curvi-linear peripheral rims 15.

The interior or lower end portion of the outer face wall 13 of head portion 11 is provided with a flat circular end plate 16 While the outer end portion of outer face 13 of head 11 is provided with a filling opening 17. The inner end portions of face walls 12 of heads 10 and 11 are joined by the intermediate elongated cylindrical handle or handle portion 14.

The outer casing or shell S of the dumbbell, which constitutes a form determining mold for the cementitious interior is preferably formed from a thermoplastic, as by blow molding, so as to provide a form which is a durable, wear resistant, yieldable member. The shell S constitutes a continuous external surface for the dumbbell and has an essentially uniform thickness except for an end closure plug 18 for closing the filling opening 17 in the head portion 10. The plug 18 has a cylindrical body 19 and a fiat top 20. The body 19 merges with a cone portion 21 from which a T-shaped anchor bar 22 protrudes. The anchor bar 22 extends into the core C when it is fluid and after curing, the core C locks plug 18 in place.

The core C of the dumbbell is formed of a solidified dense cementitious material, such as cast concrete 23, preferably loaded for weight and economy, with iron scale 24 dispersed evenly in the concrete 23.

The handle or handle portion 14 is slightly wider at its central position and tapers outwardly in both directions. The inwardly tapering frusto-conical inner face walls 12 and the extremities of the handle 14, merge along curvilinear neck junctions or annular fillets 25. In crosssection, the contour of the fillets 25 are concaved outwardly so as to receive tangentially the end portions of the inner face walls 12 and the end portions of the handle 14. Any abrupt or sharp, as opposed to gradual, change in direction at the fillets 25 causes a tendency of the dumbbell to break at that point, when dropped. Perhaps this may be compared to notch embattlement with respect to metals.

The flat end plate 16 facilitates supporting the shell S on a flat surface for filling. When the shell S is sitting on end plate 16, the smooth inner surface of inner face wall 12 of head 10 acts as a funnel to direct the fluid concrete 23 into the handle 14 and thence into head 11. The surface of the upwardly, i.e., inwardly diverging outer face wall 13 of head 11 facilitates the even spreading of concrete 23 within head 10 so that voids are maintained at a minimum. The converging inner face wall 12 of head 11, likewise, facilitates filling in that, as the head 11 approaches its filled condition, the slope of wall 12 conforms to the natural slope of the concrete 23 while the maximum head or weight of the concrete 23 is concentrated toward the longitudinal axis to facilitate spreading or urging of the concrete against the walls 12 and 13 of the shell S. In much the same manner, the contour of head 10 facilitates filling of the concrete 23 there- In the commercial manufacture of dumbbells of the present invention, after molding of the hollow polyethylene shell S by such forming operations as may meet the demands of the economic manufacture, the casings or shells S are erected in vertical position, as indicated in FIG. 3, with their lower closed heads 11 seated within the circular receiving portions 26 of a strap-type fixture 27 (see FIGS. 3, 4 and The circular receiving portions 26 of the fixture 27 are joined by intermediate spacing portions 28 while the ends 29 of the strap fixture 27 are supported by brackets 30, to which they are removably secured by bolts 31,

mounted on a vibration table 32. Such vertical disposition of the shells S presents the openings 17 of the heads in alignment with the spouts 32 of a filler trough 33. The filler trough 33 is pivotally mounted as at 34 upon a standard 35 extending vertically from a filling apparatus base 36. The base 36 mounts the vibratory table 32 upon which the fixture 27 is supported. The trough 33 includes an operating arm 37 engaged by chain 38 which by linkage arm 39 provides control of the tilting position of the trough 33, through a manually operable crank 40 by way of any desired type of linkage (not shown).

With respect to the particular filling mechanism shown, by way of illustration, reference may be had to the copending application of Forrest H. James, Jr. et al. en titled Dispenser, filed Sept. 16, 1963, Ser. No. 308,975, now Patent No. 3,270,390, which application is specifically directed to the filling mechanism here shown. It will thus be understood that the present invention is not concerned with the filling mechanism itself. Obviously, other types of filling means and agitating means for the casings may be provided.

A relatively light fluid slurry of cementitious material, preferably including an adequate proportion of iron scale or mill scale 34, to insure an appropriate weight for the finished article, is placed within the trough 33 which has .4 been pivotally moved whereby each of its separate spouts 32 is inserted in the opening 17 of the shell S mounted on the fixture 27. As the slurry is deposited, the shell S is vibrated in such manner as to insure complete filling 0f the shell S while precluding or minimizing the formation of voids in the resulting core C. Furthermore, vibration of the shell S during the filling operation assures that the slurry will pass through the handle portion 14 and fill head portion 11.

After the complete filling of shell S with the slurry, including the weighting iron scale 24, a terminal period of vibration insures complete absence of voids. Before, at least the upper portion of the concrete 23 is solidified by curing in the region of the opening 17, and the closure plug 18 inserted.

When the closure plug 18 is fully inserted, the inner peripheral bead 40 which sourrounds the body 19 of the plug will engage the inner edge of the peripheral lip 41 of opening 17 to retain the plug 18 while the concrete 23 is curing and shrinking. In such disposition of the plug 18, the anchor bar 22 is inserted in the concrete 23 while the concrete 23 is fluid. Upon the final curing, the plug 18 is permanently locked into the monolithic cementitious material by the anchor bar 22.

It is of significance that the concrete 23, upon drying, tends to shrink. The contour of the barbell shell S is such as to take advantage of this. It will be noted that the inner face walls 12 taper toward each other and have smooth interior surfaces. Indeed, the entire interior surface of the shell 8 is smooth, as illustrated in FIG. 1. Furthermore, the handle 14 is elongated along the longitudinal axis and the entire dumbbell is symmetrical and concentric about the longitudinal axis.

Therefore, when the concrete 23 is received in the shell S, the solidifying and contraction of the concrete 23 in handle 14 urges the opposed cone-shaped concrete, adjacent in the inner walls 12 of the shell S, toward each other, thereby tending to permit it to shift inwardly with respect to the smooth surfaces of the shells and bind thereagainst. Thus, the solidified concrete core C cannot shift appreciably.

From the foregoing it will be seen that the article of the present invention provides an improved dumbbell having an exterior wear resistant but yieldable and attractive surface providing a smooth comfortable grip and surface free from danger of injury to articles against which it may be impinged. Sriking of the dumbbells one against the other or against other objects will not produce the loud noise associated with the clashing of wood or metal dumbbells. Further, it will be seen that by a judicious adjustment of the proportion of iron scale in the cementitious mixture of the weight that it may be readily adjusted. Upon curing of core C, the external casing or shell S provides a permanent tightly engaged coating for the internal rigid heavy cement body 23 within the shell S. By the present method and through the selection of the material as suggested, it will be seen that the dumbbell is economic in construction and manufacture and provides an article having a substatnially long life free from deterioration by action of the elements.

It will be obvious to those skilled in the art that many variations may be made in the arrangement here chosen for the purpose of illustrating the present invention without departing from the scope thereof as defined by the appended claims.

What is claimed as invention is:

1. A dumbbell comprising: a

(a) a unitary shell formed of resilient shock resistant plastic, said shell including:

a tubular handle open at both ends; and

a pair of opposed hollow heads connected to the ends of said handle, said heads being substantially larger than said handle, and having outer face Walls and opposed inwardly tapering inner face walls, the inner walls converging toward the ends of said handle,

said tapering inner face walls being smooth and engaging the maximum diameter of each head at an acute angle, each of said inner face walls having the shape of a frusto-conical section, said heads each having a hollow interior communicating with the hollow portion of said handle, said heads having a common axis with said handle; and

(b) a monolithic core of solidified cementitious material substatnially filling the interior of said heads and said handle.

2. The dumbbell as set forth in claim 1 wherein said outer face walls of said heads diverge outwardly, the inner and outer face wall of each head being frusto-conical in shape and abutting each other at their respective bases, said bases being joined by an arcuate rim.

3. The dumbbell set forth in claim 1 wherein said inner face walls and the ends of said handle merge with each other along annular arcuate fillets.

4. The dumbbell set forth in claim 1 wherein said cementitious material includes concrete and will scale.

5. The dumbbell set forth in claim 1 including a plug protruding through one end of the outer face wall of one of said heads, said plug having a portion thereof anchored in said cementitions material of said core said portion being at a right angle to the exterior portion of said plug.

References Cited UNITED STATES PATENTS RICHARD C. PINKHAM, Primary Examiner WILLIAM R. BROWNE, Assistant Examiner 

